Problem: If $x \star y = x(y-7)$ and $x \barwedge y = 2x-6$, find $5 \barwedge (2 \star 4)$.
We don't need to find $2 \star 4$ because $x \barwedge y$ depends only on the left operand. Find $5 \barwedge y$ $ 5 \barwedge y = (2)(5)-6$ $ \hphantom{5 \barwedge y} = 4$.